PROJECT SUMMARY The failure of a drug during the development process is extraordinarily costly and dangerous. Indeed, it can take upwards of 10 years and $2-3 billion to develop just one drug, and much of that cost is derived from other candidates that fail. Most of these failures occur towards the end of the development process when the costs are highest and when the drug is exposed to the most patients. One of the most common reasons for failure is a compound?s propensity for causing cardiac arrhythmias in patients. In some rare cases, these cardiotoxic effects aren?t even detected during clinical trials and are only discovered once the drug is exposed to the population at large, resulting in harm to patients and a costly withdrawal from the market place. Consequently, the FDA has mandated that all new drugs be tested for cardiotoxic effects, but they and the drug industry realize that current screening tools fall short. This has led to a growing market for screening tools that are more predictive than existing technologies. Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) represent a promising avenue towards building high-representative in vitro tissue models for preclinical drug screening. However, most iPSC-CM models do not develop into mature, adult-like tissue and fail to recapitulate some in vivo drug responses. NanoSurface Biomedical is applying for Phase 1 SBIR funding to develop a combinatorial bioreactor system to enhance the maturation of cardiac stem cells for improved drug-induced cardiotoxicity screening. The bioreactor will generate tissues that are more functionally mature and can be fed into various down-stream assays. We hypothesize that the combination of nanoscale structural cues, mechanical stretch, and electrical stimulation will improve cardiac structural and functional development to enable the collection of cardiotoxicity data with more predictive capacity. To test these hypotheses, this project will focus on the design and fabrication of a combinatorial bioreactor that can reproducibly and reliably apply the required stimuli (Aim 1). New methods of fabrication must be tested and implemented to ensure production of highly precise nanoscale architectures that promote cell development. Reliability and selection of actuators for mechanical stretch will also be undertaken. The company will develop hardware and software for in situ electrical stimulation that is applied in a spatiotemporally coordinated manner with the other external stimuli. Lastly, the company will develop protocols and validate the hypothesis that these combinatorial cues can enhance iPSC-CM maturation (Aim 2). This will be assessed via a suite of structural, electrophysiological, and functional metrics combined with statistical analysis. These data will be used to assess the validity of the approach for eventual scale up during Phase 2, and for commercial release and market delivery in Phase 3. Successful validation of the company?s combinatorial bioreactor will produce an innovative new product aimed at relieving critical deficiencies in preclinical toxicity models and reduce cost and time in the drug development process.